1978 KTM 250 GS
Specifications and workshop reference information for the 1978 KTM 250 GS, including engine, chassis, service data and setup details.
Note: Specs are compiled from factory data, manuals and owner feedback. Bikes vary — if yours is different, jump into the forum and share it.
General Specifications
| Engine Type | Air-cooled 2-stroke single-cylinder |
| Displacement | 249 cc |
| Bore × Stroke | ~72.0 × 60.0 mm |
| Compression Ratio | ~11.0:1 |
| Maximum Power | ~34 hp |
| Maximum Torque | N/A |
| Carburetor | Bing / Mikuni ~36–38 mm |
| Lubrication | Premix |
| Fuel Mix Ratio | 25:1 |
| Ignition | Motoplat / Bosch (points) |
| Spark Plug | Bosch / NGK equivalent |
| Spark Plug Gap | ~0.5–0.6 mm |
Transmission
| Transmission Type | 6-speed manual (GS wide ratio) |
| Clutch | Wet multi-plate |
| Primary Reduction | ~3.0 |
| Final Reduction | ~3.5 |
| Overall Reduction | N/A |
Dimensions
| Overall Length | ~2150 mm |
| Overall Width | ~820 mm |
| Overall Height | ~1150 mm |
| Wheelbase | ~1420 mm |
| Ground Clearance | ~300 mm |
| Fuel Tank Capacity | ~10.0 L |
Chassis
| Frame Type | Steel single cradle |
| Caster Angle | ~27° |
| Trail | ~110 mm |
| Front Suspension | Marzocchi telescopic forks |
| Rear Suspension | Twin shock (Bilstein / WP early type) |
| Front Suspension Travel | ~250 mm |
| Rear Suspension Travel | ~220 mm |
Brakes & Wheels
| Front Tire | 3.00-21 |
| Rear Tire | 4.00-18 |
| Front Brake | Drum |
| Rear Brake | Drum |
250cc Other Specs
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